1. Technical Field
The invention relates to a sliding body, in particular a ski or runner, as they are usable with apparatus and vehicles, particularly for snow and ice, but for water sports also.
2. Description of the Related Art
Essential for good sliding properties as well as for directional stability and steering ease or manoeuvrability resp. and also for durability under shock-like and vibrating stresses is the oscillating response of the body or its external parts getting in interaction with the sliding medium. According to usual technique substantially only he oscillating response in very low frequency ranges is taken into consideration. In this way spacious or macroscopic phenomina can be taken into account which, however, left open desires for various optimizations up to now.
Therefore, the task of the invention is the creation of sliding bodies further improved with regard to the aforesaid points. The basic idea of the solution according to the invention here is taking into account medium and higher frequency ranges or characteristic frequencies and above all, the resonance spectra in those ranges.
To the the task as set above the solution according to the invention is defined by the features of the patent claim 1 or of the subordinate claims. The features of the dependent claims present inventively essential integral parts or further developments resp.. The subject matters thereof are practicable each alone, however, with special advantages in the various possible combinations.
The basic idea of the invention consists in the realization of at least one vibration-reactive subdivisional structure with at least one sequence of distinct spatial, superficial or linear region, which present at least one vibration parameter, particularly a local spatial or suberficial mass density, resistance to bending deformation or dampening, which is dimensioned or distributed differently in relation to at least one adjacent region or within the region itself. With advantage there is provided at least one sequence of a plurality of distinct regions with differently dimensioned or distributed vibration parameters. Further an essential feature consists in providing at least one periodic sequence of distinct regions with differently dimensioned or distributed vibration parameters. In particular at least one sequence of distinct regions with differently dimensioned or distributed vibration parameters is considered, which sequence extends along a surface of the sliding body, and which e.g. may comprise at least one sequence of distinct regions extending substantially in the interior of the sliding body and having differently dimensioned or distributed vibration parameters, particularly at least one sequence of distinct regions having differently dimensioned or distributed vibration parameters and extending multidimensionally or in a plurality of spatial or superficial directions.
In further developing the invention at least partially different distance sequences between the distinct regions and/or different vibration parameter variations from region to region are assigned to the different dimensions or spatial or superficial directions resp., in which a sequence of distinct regions with differently dimensioned or distributed vibration parameters extends, in which context particularly said distinct regions with differently dimensioned or distributed vibration parameters are arranged serially or grid-like in at least one area, particularly within a surface section of the sliding body.
The distinct regions of different vibration parameters may be arranged in a distribution in at least one surface section and/or at least one wall section of a cavity of the sliding body or along at least one edge of the sliding body. In a further variation the distinct spatial, superficial or linear regions comprise at least one section with values of one or more vibration parameters being higher in relation to its vicinity.
In a further variation of the invention there are sections provided having vibration parameters, particularly a surface-related local mass density or a local deformation resistance, which is higher in relation to at least a part of their vicinity due to elevations within a surface of the sliding body, said elevations being formed particularly rib-, wave- or hump-like and preferably formed as mounted elements in the range of a sliding body surface. A preferred realization provides sections having vibration parameters, in particular a surface-related local mass density or a local deformation resistance, which is higher in relation to at least a part of their vicinity, said sections being formed by elements embedded in a basic material. Such embedded elements e.g. may consist of at least one material different from the basic material, in particular of a material of higher density or of a higher elasticity modulus, preferably of heavy metal.
An important further development provides spatial or superficial regions having at least one section with values of one or more vibration parameters, particularly a surface-related local mass density or a local deformation resistance, being minor in relation to their vicinity. Such sections e.g. are formed as excavations or openings within a surface of the sliding body, particularly also as depressions in the form of notches or callote shells. Essential is also the possibility to realize the sections with values of at least one vibration parameter minor in relation to their vicinity, in particular of surface-related local mass density or local deformation resistance, by means elements embedded in a basic material. Such embedded elements may consist of at least one material different from the basic material, particularly of a material of lower density or of a lower elasticity modulus, preferably of light metal.
An inventive idea leading further is characterized by at least one vibration-reactively subdivided surface layer or at least one layer section, particularly in the form of a coating by granulates, lacquer or foil, preferably with metal contents.
Further essential according to the invention is a realization in which at least in a part of a vibration-reactive subdivision the center distances of subsequent distinct spatial, superficial or linear regions or the distances between certain sections within subsequent distinct regions are dimensioned at least approximately equal. There it is often sufficient and advantageously simple that at least in a part of of a vibration-reactive subdivision the extremal or average values or the distribution of the values of at least one vibration parameter in subsequent distinct regions are dimensioned at least approximately equal. However, for optimazation it is generally advisable, at least in a part of a vibration-reactive subdivision, to dimension the center distances of subsequent distinct regions or the distances between certain sections within subsequent distinct regions variable with regard to a predetermined sequential direction.
With certain effects which are advantageous depending on the application conditions, there the center distances of subsequent distinct regions or the distances between certain sections within subsequent distinct regions may be dimensioned progressively or degressively variable in a sequential direction in at least a part of a vibration-reactive subdivision. Here again it may be essential to dimension the extremal or average values or the distribution of the values of at least one vibration parameter in subsequent distinct regions variable with regard to a predetermined sequential direction, that is with specific effects with regard to a predetermined sequential direction progressively or degressively variable, particularly e.g. in the form of a sequence of distances or values being unidirectional at least by sections. In particular a sequence of distances or values oscillatingly variable at least by sections is considered. In this context a particularly essential variation consists in that the distinct regions subdivide a total or partial dimension of the sliding body in accordance with the values of a predetermined progression.
Thorough investigations and practical experiments have shown that the sequence of distances and/or subdivisions and/or values should be dimensioned at least approximately according to a harmonic progression, in special cases eventually according to a geometric progression.
A rapid further development of the inventive ideas consists in providing at least one vibration-reactive subdivision which comprises at least one superpositional structure extending linearly, superficially or spatially and containing at least two sequences of distances and/or subdivisions and/or values. There a specific mode of realizing this feature may comprise at least one vibration-reactive subdivision with at least one superpositional structure extending linearly, superficially or spatially and containing at least two equidistant sequences.
The values and/or distribution of at least one vibration parameter in the subsequent distinct regions e.g. may be dimensioned at least approximately equal within each equidistant sequence, however, preferably these values are dimensioned at least by sections in accordance with at least one harmonic or at least one geometric progression or in accordance with a superposition of such progressions.
The features according to the invention have been investigated and optimized particularly thoroughly with skis and runners resp.. Therein it has proved essential that at least one vibration-reactive subdivision is realized which has at least one sequence of distinct spatial and/or superficial and/or linear regions extending in the longitudinal or running direction of the ski or runner body and having at least one vibration parameter each, which is dimensioned or distributed differently in relation to an adjacent region.
As to the common basis of the variations according to the invention the following hint is given: Vibration-reactive in the sense of the invention is a subdivision having distinct or in relation to their vicinity different and subsequently, particularly in mutual coupling arranged regions, which with regard to their own vibration parameters or with regard to vibration parameters defined by coupling with their vicinity are in the range of characteristic frequencies or of the characteristic frequency spectrum of a body given as the initial object or of a body to be realized with certain properties. A quantitative delimitation of the vibration reactivity, therefore, must comply with conditions of the relevant application. Such delimitation can be obtained theoretically or by calculation or by experiment on the basis of well-known criteria, often even directly evident. Accordingly, the effect of such a vibration-reactive subdivision is directed to a desired design of the characteristic frequency spectrum. The target may be e.g. densifying the characteristic frequencies, i.e. increasing the number of characteristic frequencies in a given frequency range, or the creation of new characteristic frequencies as well as an equalization, enhancement or lowering of the curve of the resonance amplitudes in a frequency range or a plurality thereof. All this can be used for a well-defined influence on sliding bodies with regard to their sliding and running properties and/or their steering ease or manoeuvrability, but also with regard to their durability under dynamic stresses.
In many cases, particularly e.g. for skis and runners, principally, however, also for carrier and buoyant bodies moved in media such as boat bodies and the like decreasing the surface friction is desired. Enhancement or new creation of relatively high characteristic frequencies in the surface range of of the body can serve for this.
On the other side, in operation sliding bodies are under continual, but uneven i.e. mostly non-periodical stress with more or less shock-like pressure forces and/or bending and/or torsion moments. A correspondingly uneven succession of short-time free (not constrained periodical) vibrations with the characteristic frequencies of the body is excited thereby. The corresponding elastic deformations mostly have undesired effects, above all in lower frequency ranges, but in these frequency ranges they are relatively difficult to be dampened. Dislocation of characteristic frequencies to higher frequency ranges or enhancement of the resonance amplitudes in these ranges by means of suitably designed vibration-reactive subdivisions can be a help here, and this often with relatively low structural expenses. In particular it has to be stated that the excitation energy from the successive shock-like stresses are absorbed in a certain distribution over the characteristic frequencies of the body. Accordingly, a relatively great number of characteristic frequencies or an increased density of characteristic frequencies as it is obtainable by applying the ideas of the invention, can be used for a general decrease of the occuring maximal vibration or deformation amplitudes, preferably in combination with a dislocation of the vibration energy into less disturbing frequency ranges.